1. Field of the Invention
The present invention relates to an antistatic photographic light-sensitive material and, more particularly, to an antistatic photographic light-sensitive material having at least one light-sensitive silver halide emulsion layer and at least one antistatic layer.
2. Description of the Prior Art
In producing and using photographic light-sensitive materials, static electricity tends to accumulate and causes many troubles. In producing photographic light-sensitive materials, this electrostatic charge is generated due to friction between photographic light-sensitive materials and rollers, friction between the support surface and the emulsion surface, or delamination of the support surface from the emulsion surface upon winding or rewinding photographic light-sensitive materials. Also, in using photographic light-sensitive materials, the electrostatic charge is generated upon delamination of the support from the emulsion surface when a photographic light-sensitive material is exposed to high humidity to cause adhesion of the light-sensitive material, or in the case of automatically developing films for movies or X-ray films. If discharge of the thus accumulated static electricity is accompanied by a light emission the light-sensitive material is exposed and, after development processing, irregular static marks such as stain-like, tree-like, or fur-like marks are formed, which seriously deteriorates the commercial value of photographic light-sensitive materials. These static marks are a quite different problem because their existence cannot be checked before development. In addition, the accumulated static electricity causes dust adhesion onto the surface of a light-sensitive material, which in turn causes secondary problems such as non-uniform coating.
Further, degree of accumulation of static electricity is so great due to hydrophobic properties of all supports for light-sensitive materials that static marks increase with the increase in processing speed and sensitivity of emulsion. Thus, there result seriously detrimental influences.
There have so far been used various materials to prevent charging of photographic light-sensitive materials. Such materials are ionic conductive materials or hygroscopic materials, and they are often used to impart conductivity to light-sensitive materials so as to rapidly remove electrostatic charges before discharge due to accumulation of static electricity takes place. These materials are used alone and in combination.
In order to directly impart antistatic properties to the support of a photographic light-sensitive materials, such materials have been known to be directly incorporated in a support-forming high molecular material or to be coated on the surface of the support. In the latter case, antistatic agents are coated as such or by mixing with a high molecular material such as gelatin, polyvinyl alcohol, cellulose acetate, polyvinyl formal, polyvinyl butyral, or the like. In addition, these antistatic agents may be added to other light-insensitive layers (for example, a backing layer, antihalation layer, interlayer, protective layer, etc.) as well as the light-sensitive emulsion layer provided on the support.
It has also been known to apply the antistatic agent to developed light-sensitive materials so as to prevent dust from adhering to developed light-sensitive materials in handling them.
Of conventionally known antistatic agents, there are few agents which exhibit satisfactory antistatic effects on light-sensitive materials having high sensitive emulsion layers especially under conditions of low humidity, and many agents suffer reduction in antistatic effect with lapse of time and cause adhesion problems under high temperature and high humidity conditions. In some cases they exert detrimental influences on photographic properties.
Thus, application of the antistatic agents to photographic light-sensitive materials has been difficult. For example, some of the polymers having acrylic or methacrylic esters with quaternary ammonium group as polymerization unit described in Japanese Patent Application (OPI) No. 125726/75 (The term "OPI" as used herein refers to a "published unexamined Japanese patent application") (corresponding to U.S. Defensive Publication No. T-955,003) and British Pat. No. 1,484,868 possess fairly good antistatic properties. However, layers coated with such polymers are sticky and tend to adhere to other surfaces and possess less resistance to aqueous compositions for development processing. Thus, they have the defect that scum of light-sensitive material is unavoidable.
On the other hand, the use of cross-linked polymers having as a polymerization unit vinylbenzyl quaternary ammonium as described in Japanese Patent Application (OPI) No. 45231/78 fails to provide a complete antistatic effect although adhesion resistance and prevention of scum during development processing are attained to some extent.